Field
This application relates generally to wireless communication and more specifically, but not exclusively, to reducing communication overhead.
Introduction
Communication networks enable users to exchange messages among several interacting spatially-separated devices. Communication networks may be classified according to geographic scope, which could be, for example, a wide area, a metropolitan area, a local area, or a personal area. Such networks may be designated respectively as a wide area network (WAN), a metropolitan area network (MAN), a local area network (LAN), or a personal area network (PAN). Communication networks also differ according to the switching technique and/or routing technique employed to interconnect the various network apparatuses and devices. For example, a communication network may use circuit switching, packet switching, or some combination of the two. Communication networks can differ according to the type of physical media employed for transmission. For example, a communication network may support wired communication, wireless communication, or both types of communication. Communication networks can also use different sets of communication protocols. Examples of such communication protocols include the Internet protocol (IP) suite, synchronous optical networking (SONET) protocols, and Ethernet protocols.
In general, wireless networks employ intangible physical media in an unguided propagation mode using electromagnetic waves in radio, microwave, infrared, optical, or other frequency bands. Consequently, wireless networks are better adapted to facilitate user mobility and rapid field deployment as compared to fixed, wired networks. For example, wireless networks readily support network elements that are mobile and have dynamic connectivity needs. The use of wireless networks also may be preferred for scenarios where it is desirable to provide a network architecture having an ad hoc topology, rather than a fixed topology.
A wireless network may be deployed on a planned or ad hoc basis to provide various types of services (e.g., voice, data, multimedia services, etc.) to users. In some implementations, one or more access points are deployed to provide wireless connectivity for access terminals (e.g., stations (STAs)) that are operating within a geographical area served by a wireless network. In some implementations, peer devices may establish a wireless network for communication between these devices.
In some scenarios, it is desirable to reduce the overhead associated with wireless communication. For example, the Institute of Electrical and Electronic Engineers (IEEE) 802.11ah standard is being developed to support sensor applications where the packet length is very short and aggressive power-save is desired. In sensor device applications, the overhead associated with a packet header (e.g., a media access control (MAC) header) may be significant compared to the size of the payload (e.g., which can be tens of bytes).
Various types of header compression have been proposed to reduce the size of packet overhead. A MAC-based packet employing security may include a MAC header, an initialization vector (IV) of eight bytes, an integrity check value (ICV) of eight bytes, and a frame check sequence (FCS) of four bytes. MAC protocol data unit (MPDU) header compression and security IV compression have been approved for IEEE 802.11-based (i.e., Wi-Fi) applications. In contrast, a proposal to reduce the size of the ICV has been rejected because some sensor use cases (e.g., a door lock sensor) may require the same level of security as other Wi-Fi use cases.